WEST INDIAN ISLANDS PORITES. 37 



coral. Minute pali, up to 5, appear in a circle too straggling to be conspicuous to the naked 

 eye. A columellar tubercle or a central pit can be made out in the less rapidly solidifying 

 calicles. 



In transverse sections the axial strand is an open, lamellate reticulum ; the cortical layer 

 is almost solid. 



Tliis coral, though about the same size, is quite different in the manner of its branching 

 and in the texture of its calicles from P. Barbados 2. Tlie forking, though irregular in the 

 sizes of the prongs, is yet not so irregular as that of the latter coral. 



There is only one stem (a) which, when gathered, was alive ; with it are two other specimens 

 which appear to belong to it, altliough doubts may be legitimately expressed : — 



b. Is a corroded forking stem with rather more conspicuous calicles than a, but with 

 traces of a very similar section to the stems and somewhat similar forking. This is only 

 provisionally placed here. 



c. Eepresents a corroded, encrusted mass, showing the section of a stem very similar to that 

 of a, and on it two young colonies, one a minute disk in its epithecal saucer, and the other 

 considerably older and rising into two forking peaks about 1 cm. high. The calicles are a 

 little smaller, and the walls rise as irregularly trabecular ridges. What little experience we 

 have of early growth stages in the Stony Corals seems to indicate that the calicles of the very 

 young colonies are smaller than those of the adults, and moreover show other differences. It 

 is clear, however, that we can only provisionally class this specimen here. 



a, b. Zool. Dept. 99. 6. 26. 11. 



c. Zool. Dept. 99. 6. 26. 10 (part). 



15. Porites Barbados 5. {P. Barbatce quinta.) 

 [Barbados (Pleistocene), coll. Franks ; British Museum.] 



Under this heading we provisionally group a number of fossilised and semi-fossUised 

 fragments of branching Porites, which for the purposes of description may be divided aa 

 follows : — 



A number of beach-worn, gravel-coloured specimens, of various sizes, but all showing in 

 the sections a remarkable contrast between an immense, openly reticular, axial strand, and a 

 comparatively thin, dense cortical layer. Many of the worn fragments consist solely of this 

 axial reticulum. 



a. The largest specimens. GeoL Dept. K. 2557. 



b. The only specimen showing remains of probably) 



young calicles near a spongy terminal ; with a [- „ R. 2193. 



microscopic slide. ) 



Ci. A great number of smaller much worn fragments. „ E. 2559 'part). 



Ci. Three fragments selected from the above with a great deal of chalky white colour 

 about them, not much worn and showing traces of the calicles. The skeletal elements 



